1. Field of the Invention
The present invention relates to a lens-fitted photo film unit having an auxiliary module. More particularly, the present invention relates to a lens-fitted photo film unit which includes an auxiliary module for imprinting information to photo film and in which the auxiliary module can operate with reliability.
2. Description Related to the Prior Art
A lens-fitted photo film unit is known in the art, and pre-loaded with unexposed photo film. The lens-fitted photo film unit includes a housing, which is constituted by a main body for containing a photo film cassette, a front cover for covering a front of the main body, and a rear cover for covering a rear of the main body. The housing is provided with a sticker with a printed decorative pattern to neaten the appearance as product.
The lens-fitted photo film unit, after taking exposures, is forwarded to a photo laboratory without removal, and subjected to operation of development and printing. The lens-fitted photo film unit after being used is withdrawn by a manufacturer and recycled. In the recycling step, the housing is disassembled into parts of various kinds. Plastic parts such as front and rear covers are pelletized and melted and reused as raw material. A flash unit and the like are subjected to inspection of performance, and reused if there is no problem.
There are types of lens-fitted photo film units having an auxiliary device for operation additional to taking an exposure. Examples of auxiliary devices are an electronic flash device, an aperture stop changer mechanism, and an information imprinting device, which optically imprints information to the photo film, information such as a numerical date of an exposure.
U.S. Pat. No. 5,978,608 (corresponding to JP-A 10-096991) discloses an example of the information imprinting device, which includes a date imprinting module and an imprinting shutter member. The date imprinting module includes a timekeeper circuit and a liquid crystal display (LCD) panel. The timekeeper circuit has information of a calendar previously written thereto. The LCD panel displays a date of an exposure. The imprinting shutter member is operable in response to a photographing shutter blade. The LCD panel indicates the date in such a manner that a background of the numerals is dark and the numerals are conspicuously bright or transparent. The date imprinting module is disposed between the main body and front cover. A light guide member is disposed on a front face of the front cover for introducing natural light into the LCD panel. The imprinting shutter member is opened and closed to cause information light from the LCD panel to become incident upon an exposure region in the photo film.
The date imprinting module is a relatively expensive product. If the date imprinting module is removed from the lens-fitted photo film unit and reused, a total cost of manufacturing the lens-fitted photo film unit may be decreased.
The light guide member receives natural light and utilizes as the information light. Furthermore, there are other ideas as light source for imprinting. For example, light-emitting diodes (LED) are used. Also, the light guide member protrudes from the front cover toward the main body, and is provided with a flash light entrance face at the protruding portion, to utilize part of flash light leaked in the housing. Those ideas are for the purpose of obtaining a sufficient amount of the information light even when brightness of a photographic field is low, for example at night.
However, the information imprinting device according to the prior art has a problem of errors in operation, because the imprinting shutter member may be shifted by shock or vibration to the lens-fitted photo film unit and a light path for imprinting information may be opened.
If LEDs as light source are used for imprinting, the manufacturing cost will increase, because of additional structures of the LEDs and a circuit for driving the LEDs. If the structure with the light guide member protruding from the front cover to the main body is used, it is likely that the information light may be too weak and insufficient for a proper exposure typically when brightness of a photographic field is extremely low.
It is conceivable that retaining hooks are used to keep the date imprinting module positioned reliably without shock or vibration. However, the LCD panel must be disposed close to a taking lens for the purpose of recording the information light into the exposure region. The date imprinting module lies in a very small space between the front cover and an exposure unit having the taking lens. Disposition of retaining hooks or the like causes the front cover to have protruding portions. This makes the housing to have a considerably great thickness in the back-to-front direction.
In view of the foregoing problems, an object of the present invention is to provide a lens-fitted photo film unit in which erroneous operation of an information imprinting device due to shock or vibration can be prevented.
Another object of the present invention is to provide a lens-fitted photo film unit capable of reliably imprinting information without use of an additional light source.
Still another object of the present invention is to provide a lens-fitted photo film unit having a sufficiently small thickness in a back-to-front direction in a state with an auxiliary device squeezed between a main body and a front cover.
Another object of the present invention is to provide a lens-fitted photo film unit in which a battery for an information imprinting device can be removed readily in disassembling operation.
In order to achieve the above and other objects and advantages of this invention, a lens-fitted photo film unit has a main body pre-loaded with photo film. A front cover covers a front of the main body. An exposure unit is secured between the main body and the front cover, for providing the photo film with an exposure. A plate-shaped auxiliary module is secured between the main body and the front cover with the exposure unit. At least one first positioning portion includes a pin or hole, and is formed in the front of the main body. At least one second positioning portion includes a hole or pin, is formed in a rear of the auxiliary module, and is fitted on the first positioning portion, the auxiliary module being subsequently kept positioned between the front cover and the main body by fitting the front cover on the main body.
In a preferred embodiment, the auxiliary module is an information imprinting module for optically imprinting information to the photo film.
The information is date information. The information imprinting module includes a timekeeper circuit for storing calendar information, and for outputting the date information by periodically renewing the calendar information. A display panel of a transmission type indicates the date information.
The information imprinting module is reset upon discontinuation of being supplied with power.
Furthermore, first and second metal contact segments are connected with the information imprinting module. A battery is connected between the first and second contact segments, for supplying the information imprinting module with power. The front cover has the first contact segment secured thereto, and upon being removed, disconnects the battery from the first contact segment, for discontinuing supply of power for the information imprinting module.
Furthermore, there is formed a photographing opening for being opened/shut by actuation of the exposure unit.
There is formed an imprinting opening behind the display panel.
Furthermore, a shutter release button is formed with the main body in an externally depressible manner. A blocking plate is movable between closed and open positions, for closing the imprinting opening when in the closed position, for opening the imprinting opening when in the open position, and for being shifted to the open position in response to actuation of the shutter release button.
The shutter mechanism has a single shutter blade including a photographing blade portion for opening/shutting the photographing opening. An imprinting blade portion is formed to extend from the photographing blade portion, for opening/shutting the imprinting opening.
The shutter release button is shiftable between an initial position and a depressed position lower than the initial position. The shutter mechanism further comprises a shutter drive lever for opening/shutting the shutter blade when the shutter release button is shifted to the depressed position. Furthermore, a transmission mechanism sets the blocking plate in the closed position when the shutter release button is in the initial position, and sets the blocking plate in the open position in response to a shift of the shutter release button to the depressed position before operation of the shutter drive lever.
The imprinting opening is disposed opposite to the shutter release button with reference to the photographing opening.
The blocking plate extends from a position lower than the photographing opening, and is movable to and away from the photographing opening. The transmission mechanism includes a driving arm formed with the shutter release button to project downwards. A driven arm is formed with the blocking plate to extend between the driving arm and the position lower than the photographing opening, for being pushed by the driving arm upon depression of the shutter release button, to move the blocking plate from the closed position to the open position.
Furthermore, a support pivot supports the driven arm in a rotatable manner.
Furthermore, a bias mechanism biases the blocking plate toward the closed position.
The bias mechanism includes a resilient arm having first and second portions, the first portion being secured to the driven arm. A stopper contacts the second portion, to prevent the second portion from shifting when the blocking plate is shifted toward the open position.
As a result, the lens-fitted photo film unit can have a sufficiently small thickness in a back-to-front direction in a state with the auxiliary module squeezed between the main body and the front cover, because of the first and second positioning portions.
Also, erroneous operation of the information imprinting module due to shock or vibration can be prevented, because the blocking plate closes the imprinting opening when in the closed position.
According to one aspect of the invention, the information imprinting module further includes a light guide member for illuminating the display panel by guiding light thereto.
Furthermore, a flash emitter emits flash light. A flash circuit board controls operation of the flash emitter. The light guide member includes a flash light entrance portion, having at least one portion protruding to a rear of the flash circuit board, for receiving entry of part of the flash light. A light exit portion applies light to a front face of the display panel by guiding the part of the flash light.
The flash light entrance portion has an inclined entrance surface.
The flash light entrance portion extends from the rear of the flash circuit board to a front thereof. The light guide member further includes an arm portion, formed with a front end of the flash light entrance portion, for extending in an L shape with reference to the flash light entrance portion, the arm portion having a rear face for constituting the light exit portion.
The arm portion is an outer light entrance portion for receiving entry of outer light from a photographic field so as to guide the outer light to the light exit portion.
Furthermore, a main body is pre-loaded with the photo film, and provided with the flash circuit board and the information imprinting module. A front cover covers a front of the flash circuit board and the information imprinting module. A light entrance opening is formed in the front cover, for uncovering the outer light entrance portion.
The light exit portion has front and rear faces at least one of which is inclined and has surface roughness.
The light guide member is formed from material including fluorescent dye.
As a result, it is possible reliably to imprint information without use of an additional light source, because the light guide member can introduce light from the flash unit to the display panel.
According to another aspect of the invention, furthermore, a battery supplies the information imprinting module with power. An opening is formed in the front cover and disposed outside the battery. An outer packaging material is secured to an outer face of at least the front cover, for covering at least part of the opening to keep the battery in a predetermined loaded position.
The outer packaging material, upon removal from the front cover, exits the battery through the opening, for discontinuing supply of power for the information imprinting module.
The battery includes first and second electrodes positioned in orientation in respectively inward and outward directions. Furthermore, first and second metal contact segments contact respectively the first and second electrodes, the first contact segment pressing the battery outwards. The outer packaging material causes the second contact segment to push the battery to the first contact segment, compresses the first contact segment resiliently, and upon being removed, allows the first contact segment to push out the battery.
The battery is a button type.
Furthermore, a battery lid is fitted in at least part of the opening. The outer packaging material covers at least part of the battery lid, and upon being removed, exits the battery through the opening, for discontinuing supply of power for the information imprinting module.
Furthermore, first and second metal contact segments contact respectively first and second electrodes of the battery, the first contact segment being away from the first electrode when in a free state. The outer packaging material presses the first contact segment resiliently for keeping the first contact segment in contact with the first electrode, and upon being removed, disconnects the first contact segment from the first electrode, to discontinue supply of power for the information imprinting module.
As a result, the battery for the information imprinting module can be removed readily in disassembling operation.